In VectorCell's Amy, the main character Lana becomes infected with a zombie virus, which progressively worsens as the game goes on, unless she maintains contact with the title character or encounters another kind of remedy.

In the trailer above, we see what the contamination does to Lana, and we're introduced to a few methods of staving off the encroaching zombosis. Although, as the video demonstrates, there's a use for being partially zombie'd, as you can shuffle through zombie crowds unperturbed. You know, for when you want to mingle with some zombies.